664736533 has 8 divisors (see below), whose sum is σ = 704538648. Its totient is φ = 625012224.

The previous prime is 664736519. The next prime is 664736543. The reversal of 664736533 is 335637466.

It can be written as a sum of positive squares in 4 ways, for example, as 141562404 + 523174129 = 11898^2 + 22873^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664736533 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664736533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664736543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1366 + ... + 36487.

It is an arithmetic number, because the mean of its divisors is an integer number (88067331).

Almost surely, 2^664736533 is an apocalyptic number.

It is an amenable number.

664736533 is a deficient number, since it is larger than the sum of its proper divisors (39802115).

664736533 is a wasteful number, since it uses less digits than its factorization.

664736533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38903.

The product of its digits is 816480, while the sum is 43.

The square root of 664736533 is about 25782.4850043591. The cubic root of 664736533 is about 872.7365862797.

The spelling of 664736533 in words is "six hundred sixty-four million, seven hundred thirty-six thousand, five hundred thirty-three".